<Well . . . freight cost alone might be justification for using switchers. <Nevertheless, I don't see a use for the regulated supplies in connection <with a bus which by definition uses on-board regulation. If the supply <actually provides the specified voltages, that's a different situation. Th <typical S-100 box, IIRC, used lots of amperes, even for just one memory The average S100 crate was +8 20A minimum and many were 25-30A on that bus never minding +12 at some 6A and -12 at same. The boards DO heat a bit and fans were typically 110V 100-140CFM models! Allison